Use case: SMARTCARD TX DMA process

Sequence diagram

SMARTCARD transmit DMA process

@startuml participant "User Application" as p1 participant "HAL SMARTCARD driver" as p2 participant "SMARTCARD_IRQHandler" as p5 participant "DMA" as p3 participant "DMAx_IRQHandler" as p4 == initialization and configuration == == Smartcard HAL Transmit DMA == p1->p2: <color: green> HAL_SMARTCARD_Transmit_DMA(&hsmartcard, aTxBuffer, DATA_TO_SEND_SIZE) note over p2 #00FF00 Transmitting data ongoing end note p2->p3: HAL_DMA_Start_IT() p3-->p2: HAL_OK p2-->p1: HAL_OK p4<-: DMAx complete interrupt p4->p3: HAL_DMA_IRQHandler note over p3 #00FF00 End of transmitting data end note p3->p2: XferCpltCallback p2->p2: Enable SMARTCARD Transmit Complete IRQ (TCIE) p5<-: SMARTCARD Transmit Complete (TCIE) p5->p2: HAL_SMARTCARD_IRQHandler p2->p1: HAL_SMARTCARD_TxCpltCallback(hsmartcard->tx_xfer_count) @enduml

Code snippet

HAL1

HAL2 

#define DATA_TO_SEND_SIZE  255

SMARTCARD_HandleTypeDef hsmartcard;

uint8_t aTxBuffer[DATA_TO_SEND_SIZE] = " **** Smartcard Communication **** ";


    /* Ensure that all required peripherals
      (USART, GPIO,NVIC,DMA etc.) are configured properly
    /*
    ...
    */

    /* Smartcard register Transmit complete user callback */
    HAL_SMARTCARD_RegisterCallback(&hsmartcard, HAL_SMARTCARD_TX_CB_ID,
                                   Smartcard_TxCpltCallback);

    /* Start a Smartcard Process in dma mode */
    HAL_SMARTCARD_Transmit_DMA(&hsmartcard, aTxBuffer,
                                    DATA_TO_SEND_SIZE)

#define DATA_TO_SEND_SIZE  255

hal_smartcard_handle_t hsmartcard;

uint8_t aTxBuffer[DATA_TO_SEND_SIZE] = " **** Smartcard Communication **** ";


    /* Ensure that all required peripherals
      (USART, GPIO,NVIC,DMA etc.) are configured properly
    /*
    ...
    */

    /* Smartcard register Transmit complete user callback */
    HAL_SMARTCARD_RegisterTxCpltCallback(&hsmartcard, Smartcard_TxCpltCallback);


    /* Start a Smartcard Process in dma mode */
    HAL_SMARTCARD_Transmit_DMA(&hsmartcard, aTxBuffer,
                                    DATA_TO_SEND_SIZE);

Key changes

  1. HAL2 uses a different DMA start API for peripheral transfers (HAL_DMA_StartPeriphXfer_IT_Opt).

  2. HAL2 provides a dedicated transmit-complete callback registration API (HAL_SMARTCARD_RegisterTxCpltCallback).